A Plot Revealed

You'll have to wait for a few days after telling Traven about Mannimarco while he consults with the council. Once he is done, talk to him again and he'll ask you to help him again. Jeanne Frasoric of the Bruma Mages Guild has not reported in for a long time. You are to go to Bruma and see if she is alright.

Inside the Bruma Mages Guild your journal will update. The entire place is in shambles with small fires and bodies everywhere. Plenty of undead creatures are roaming the building that you'll have to destroy. Fight your way downstairs on the right and through the basement. You'll come back upstairs on the opposite side of a burning wall that collapsed and blocked the direct route up to the top floor. Go up there and you'll be confronted by a Necromancer looking for a fight. Kill her and J'skar will pop out to talk to you. He is the only survivor and explains that the King of Worms is responsible for this tragedy. Report your findings back to Traven to complete the job.

You can now request advancement from Raminus. He'll name you a Wizard and teach you the spell Wizard's Fury, a multiple element Destruction spell.